Category Archives: Effusive eruption

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Photos by Dr. Edward Kohut, all rights reserved, used by permission, 2009
Many times people think that volcanic eruptions affect the economy through the destruction inflicted upon the landscape during an eruption: lahars and pyroclastic flows destroying bridges and homes, ash ruining crops and water, lava flows overunning communities. However, in Hawai’i, a new effect of volcanism has been seen in the agriculture of the state. The volcanic fog – or “vog” as its called – has been causing major problems with farms on the Big Island of Hawai’i. Since the new activity at Halemaumau (see above) began last year, Kilaeua has been spewing much larger volumes (2-4 times more) of volcanic gases such as sulfur dioxide, carbon dioxide, water and carbon monoxide than in previous years. These gases form a brown fog that is caustic to most animals and plants. The sulfur dioxide, in particular, has caused many crops to fail thanks to the production of sulfuric acid with the sulfur dioxide interacts with water – think of it as a very concentrated version of “acid rain” that is seen in the eastern United States.
The solution to this would either be to build “vog-proof” air-filtering greenhouses or planting a limited set of plants that seem to withstand the effects of the vog. Alternately, one can hope that the gas emissions from Kilaeau will return to lower levels, allowing for the plants to survive. In any of these cases, the growers on the island face a large financial hardship in order to keep their businesses alive in the face of the volcano. This passive destruction of plants by Kilaeua shows how even when a volcano seems to be benign, it can inflict millions of dollars of damage on the local economy.

The “eruption watch” continues at Redoubt … Saturday revealed that things are getting hotter at the summit near the 1989/1990 dome (see picture above that made Redoubt famous in 1989). The overflight of the volcano revealed new holes in the summit glacial and a multitude of muddy streams formed from the meltwater. This area of very intense fumarolic activity is just below the 1989/1990 dome (~7,100 feet) and has been growing over the past few days. They also report an area at ~9,000 feet on the volcano that shows signs of ice collapse, indicating heat from underneath the snow and ice (similar to what was seen at Mt. Saint Helens when it reactivated in 2004).
The Seattle PI article linked here does seem to get a little confused when it comes to the potential volcanic products at Redoubt. From the article:

“Geologist Jennifer Adleman said magma is a combination of three phases: liquid rock plus a gas and crystals than can form sort of a froth that works its way up the mountain.“A lot of scientists refer to is as a crystalline mush,” she said.”

Now, I’m not certain what Adleman is referring to in her quote, but I’ve never heard of the frothy material as a “crystalline mush”. Not to say that is an inaccurate description, but usually mushes are referred to when the magma is at depth in the volcano. This is more like a foam, with the liquid and crystals entrained in a magma that is packed with bubbles that form as the magma decompresses. If those gases get bottled up before the volcano erupts, you could get an explosive such as what happened at Mt. Saint Helens in 1980. If not – if the gases are allowed to be more passively released, lets say if the magma stalls as it comes up – then we might get the toothpaste-style eruption we saw in the most recent Saint Helens activity.

Right as Yellowstone is getting interesting (or at least had signs of interest), Eruptions is going on a bit of a break again starting January 2. This time it is because I’m off to the North Island of New Zealand to do some field work. I’ll be headed to Tarawera (hopefully both the 1305 and 1886 eruption deposits), Taupo, Tongariro, the area around Rotorua and maybe even White Island (amongst other). I won’t have my MacBook, but I will have my iPod Touch, so I’ll try to keep track and make brief posts if something big comes up, but feel free to use this post as a clearinghouse for any news or articles you run across until I return on January 16th.Happy 2009 to all the Eruptions readers!

Although this news isn’t as threatening as the title of the article implies: HAWAII LAVA FLOW NEARS NATIONAL PARK, it is still some news as it could be the first lava flow to cross into the park in over a lava. The flow itself is headed towards what is called the “Waikupanaha ocean entry” on the southeast side of the island. The lava flow has about one mile to go before it reaches the Pacific Ocean, but it has travelled several hundred feet (maybe 100 meters) over the last 10 days according to Park Rangers and USGS geologists monitoring the flow’s progress.
Of course, compared to your average pyroclastic flow or lahar, traveling at tens to hundreds kilometers per hour, tracking this lava flow is a little bit like watching paint dry (except, of course, it is lava). It shows the whole different level of volcanic hazard presented by Hawaiian volcanism versus Plinian (explosive) volcanism, where the level of concern at the park can be summed up with “Our idea is not to control and prevent. Our idea is to educate.”

Klyuchevskoy has already had a busy year and now we have some recent photos showing a lava flow that is snaking down the side of the volcano. The website with the lava flow image has a pile of other great eruption photos of Klyuchevskoy over the last couple of years and well worth the time to look through them all – the volcano is definitely one of those classic arc volcanoes in both shape and activity.

Sounds like we’re beginning to get a better idea of what is erupting in Ethiopia. Ghezahegn Yirgu, a geologist at Addis Ababa University, reports that Dalla FillaDalaffilla Volcano is the source of the eruption. Again, the eruption is being characterized as “lava flows” rather than an explosive eruption, which may be surprising considering the amount of volcanic gases being released (see Boris Bechnke’s highly useful comment). However, some mostly effusive eruptions have released a lot of volcanic gases in the past – see Laki, Iceland in 1783 – so a preponderance of flows at Dalla Filla Dalaffilla would not be shocking.
Now, there is surprisingly little information I can find about Dalla Filla – in fact, it doesn’t even appear in the GVP database or, for that matter, almost anywhere on the internet. The volcano is located, according to the article linked above, about 20 km north of Erta Ale, so it is in a region of active East African Rift volcanism. The map above (from the USGS) shows all the volcanoes in the area that have known eruptions since 1800, so unless Dalla Filla is being confused with Dallol, it might be the first eruption of the volcano in quite some time. I’ll update once I can find more information on Dalla Filla (and feel free to comment here if you know more than I).REVISED (11/6/08): Apparently, the volcano in question is Dalaffilla, which shows up in the GVP website (Thanks Ole and Ron). There isn’t much information on Dalaffilla, except that, surprisingly, it appears to be a silicic volcano. The reports I’ve read so far seem to indicate that lava flows have spread out over a large area, which would suggest a low viscosity (i.e., basaltic) lava. Thanks to the Eruptions readers who dug out some great information.

In one of the most oddly worded articles I’ve seen from the BBC, a lava flow from Erta Alean unidentified volcano in the Erte Ale range in Ethiopia has erupted a significant amount of lava. The headline states “Ethiopia volcano sets lava record”, which is strange on multiple counts, but mostly because I’m not familiar with any “lava records”, who might keep track of them and what, exactly, this “lava record” is. In fact, they don’t even mention it in the article itself. They do, however, point out that lava from this eruption has covered 300 square kilometers, which is a decent chunk of real estate, but no mention is made of how long it took to do this (or what type of lava, for that matter, but it is likely basalt). So, take this article as you will. The take home message is that Erte Alea volcano in the Erta Ale range, near Alu, has had a significant eruption with some associated earthquakes to go along with it.
Erta Ale is located on the East African Rift in Ethiopia – part of the Erte Ale Range – and is a fairly active shield volcano that erupts basaltic lava flows from both the central vent and from fissues, along with sometimes have a lava lake in the main caldera. These eruptions aren’t too much of a danger to the people who live near the volcano as it mostly issues lava flows rather than erupting explosively. It hasn’t erupted since 1967 according to the GVP, however, the volcano did erupt in 2005 (see above), displacing thousands of people.NEW INFORMATION (2200 Pacific Time)
Just got this email about the eruption in northern Afar, Ethiopia. Sounds like it has released a significant amount of sulfur into the atmosphere:

Satellite instruments detected an eruption in northern Afar, Ethiopia
on November 3. The eruption first manifested itself as a large sulfur
dioxide (SO2) cloud drifting eastwards over the Arabian peninsula,
detected by the Ozone Monitoring Instrument (OMI) and the Atmospheric
Infrared Sounder (AIRS). MODIS data from the University of Hawaii’s
MODVOLC hot-spot monitoring tool (http://modis.higp.hawaii.edu)
confirmed an extensive hot-spot (presumably lava flows) near Alu
volcano, in the northern part of the Erta ‘Ale range. Details are
still sketchy and these observations are as yet unconfirmed from the
ground.A total of 0.1-0.2 Tg of SO2 was measured in the eruption cloud by OMI
at ~1100 UT on November 4, by which time the SO2 cloud had reached
southern Iran. Using the OMI SO2 data and radiosonde soundings,
observed SO2 cloud drift yields a preliminary estimate of the eruption
onset time of 1400-1600 UT on November 3.

The headline for this entry sounds more dramatic than it is, but one of the last structures in the ill-fated Royal Gardens subdivision on the big island of Hawai’i finally met its fiery demise over the weekend. For those of you unfamiliar with the plight of the subdivision, Royal Gardens is part of Kalapana, and it was unfortunately situated quite close to the Pu’u O’o rift that has been erupting since 1983. Most of the subdivision has been overrun by lava flows since then, but one of the last two structures still being used was done in by the basaltic lava. The first link has a great map showing the October lava flows and where they have gone, along with some stills of the flows overtaking the house (in the video).

It seems that a new fissure eruption has begun at Piton de la Fournaise on Reunion Island in the Indian Ocean*. In fact, the report goes onto say that a small lava lake has formed at the main crater of the eruption. This marks the first eruption at Piton de la Fournaise since March 2007.
Piton de la Fournaise is a large shield volcano associated with the Reunion Island Hotspot. The volcano has frequent eruptions, mostly in the form of effusive lava flows of basalt, similar to the Hawaiian volcanoes. This could be an interesting new eruption because the initial eruptions suggest this is a flank eruption outside the caldera, but this might just be a product of a mistaken report.
*Update 9/21/08: Thanks to Anthony for noticing that Reunion Island is in the Indian Ocean, not the Pacific. Sorry about misplacing the island!

Not sure how it was kept quiet for most of the week (well, at least to me), but geologists at the HVO have noticed a new lava lake in Halemaumau Caldera on Kilauea (Hawai’i). The lava lake is around 330 feet (~100 meters) below the crater rim and ~160 feet (50 meters) across with sections of reddish, glowing lava and black crust on the surface. It seems that an explosion on Tuesday helped reveal the lava lake from the surface. The USGS has posted some video of the lava lake for your enjoyment. There are only a few active lava lakes worldwide (such as those at Villarrica in Chile and Erebus in Antarctica), so it is always exciting when a new one forms. The longevity of lava lakes is controlled (partially) by the supply rate of magma to the vent area, so it will be interesting to see how long it lasts.UPDATE 9/7/2008
Here is the official word on the lava lake from the USGS:

For the first time since the new vent opened in Halema`uma`u Crater on
March 19, HVO scientists in a helicopter hovering over the crater were
able to see the surface of a sloshing 50 m (160 ft) diameter lava lake
about 100 m (330 ft) below the vent rim. HVO scientists have speculated
that a lava pond existed a few hundred meters below the vent, but have not
been able to get visual confirmation until this morning.
A second viewing early this afternoon revealed a roiling pond with
multiple bursting bubbles changing into a central upwelling circulation
pattern. The lake level dropped slightly before the cycle restarted. This
behavior has been witnessed before, most recently in Pu`u `O`o vents and
the July 21 lava ponds on Kilauea’s east rift zone, and is known as ‘gas
pistoning.’ One model explains pistoning as small gas bubbles coalescing
into larger bubbles beneath a crust on a lava pond, rising to the surface,
and then bursting. The released pulse of hot gas carries rock dust from
the collapsing vent walls, bits of the lava lake crust, and small amounts
of spatter.
The Halema`uma`u vent has produced six significant explosive eruptions in
the past 5.5 months, most recently on September 2, 2008 at 8:13 p.m.
H.s.t., during which noteworthy amounts of fresh lava spatter and lithic
material (rock fragments and dust) were ejected on to the crater rim. Just
prior to this event, incandescence from the vent was almost nonexistent
except for brief pulses of glow.
Nearly eight hours later, Kilauea’s summit abruptly inflated, signaling
the end of 39 hours of deflation. Summit deflation-inflation (DI) events
have been observed at least 20 times since the Halema`uma`u vent opened.
Each DI event has been interpreted as the fall and subsequent rise in
magma levels beneath the summit.
Less than 8 hours after inflation started, episodic tremor bursts began
which are visible at night as pulses of bright incandescence every 5-6
minutes. Episodic tremor bursts have been a nearly constant feature of
the Halema`uma`u vent over the past few months and were one of the early
pieces of evidence pointing toward a gas pistoning source.
This unusually bright incandescence over the past two nights and the
volume of material erupted on September 2 are consistent with a lava
surface at relatively shallow depths beneath the vent. Molten lava is not
directly visible from the Jaggar Museum overlook, but that vantage point
provides excellent views of the glowing vent at night.
Jim Kauahikaua, Scientist-in-Charge
USGS Hawaiian Volcano Observatory